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connectivityZONE Products for the week of September 6, 2008
NEC Electronics Says…
Expands Wireless USB Portfolio with New Host Controller
PCIe-based controller delivers higher throughput, higher performance for laptops
NEC Electronics has expanded its suite of Wireless USB devices with the introduction of the uPD720171 Wireless USB host controller. Building on the company’s first host controller (part number uPD720170), the new uPD720171 controller for PCI Express bus interfaces, enables high-speed, wireless data transmission between PCs that have MiniCard or Half-Minicard expansion cards and PC peripheral devices such as wireless hubs, printers, external storage equipment and digital cameras. The new host controller also provides laptop computer connectivity through an ExpressCard slot. Providing greater throughput and higher performance than previous host devices, the uPD720171 controller enables consumers to enjoy wireless lifestyles while maintaining wired USB functionality and ease of use.
“As the consumer appetite for wireless connectivity increases, the industry is requiring reliable, standardized interface solutions that can transmit data at speeds equivalent to wired USB connections,” said Yoshiyuki Tomoda, Group Manager, SoC Systems Division, NEC Electronics Corporation. “By providing these performance levels, our new uPD720171 host controller is helping bring the industry closer to mainstream adoption of advanced wireless technologies.”
Certified by the USB Implementers Forum (USB-IF), the uPD720171 controller conforms to the Wireless USB 1.0 specification and also to the Wireless Host Controller Interface (WHCI) specification developed by Intel with support from Microsoft, NEC Corporation, Philips, Texas Instruments and other experts in Wireless USB technology.
Capabilities of Wireless USB
Developed by the USB-IF, Wireless USB technology is an extension of the current USB 2.0 standard, which has been hailed as the next-generation interface standard for computers and multimedia consumer electronics devices. Products based on Wireless USB technology can transfer up to 480 megabits per second (Mbits/s) of data, comparable to wired USB 2.0 connections, within a maximum range of 10 meters. NEC Electronics’ new controller can transfer up to 480 Mbits/s within a maximum range of three meters.
Unwiring the cable connection frees users from having to make cumbersome and unsightly wired connections and enables them to enjoy high-speed data access wherever wireless connectivity is possible. Wireless USB technology is currently making it possible for designers to expand the boundaries of computing and digital entertainment to discover new ways for consumers to enjoy digital media.
NEC Electronics has played a central role in making the current USB 2.0 standard one of the most successful interfaces in the history of personal computing. Along with Intel Corporation and other industry leaders, NEC Electronics is a core member of the USB-IF, which developed the USB and USB 2.0 specifications and is currently developing the USB 3.0 specification. Since launching volume production of USB 2.0 devices in 2000, NEC Electronics has shipped an industry-leading 150 million units worldwide.
EN-Genius Says…
I’m a bit dubious about the technical merits of Wireless USB but, given the consumer tendency to choose convenience over performance, NEC was smart to latch onto what promises to be a booming market with its series of Wireless USB products. NEC says that in addition to the inherent speed advantage that its WAC-based uPD720171 controller enjoys over a comparable HWA-based solution, its chip set has been designed to make the most efficient use of the bandwidth it has available while minimizing the processing load on its host system. They’ve done this by using hardware acceleration to handle as much of the handshaking in the WACI MAC/air interface as possible. This allows the host driver software to simply write to the controller control registers to configure it and handling the data stream with straightforward DMA-based transfers.
The uPD720171 includes a WACI host controller interface core licensed from Intel. This is no surprise since Intel is the developer and driving force behind the WACI standard that’s based on a PCI/PCIe host system interface and can theoretically delivers up to 200 Mbit/s worth of effective throughput from the raw 480 Mbit/s USB 2.0 channel when moving large blocks of data. Of course the higher protocol overhead involved with moving shorter blocks and dealing with re-transmits of dropped packets could quickly cut this in half, but I digress…
As NEC’s release indicates, their host controller uses an external PHY/radio. Until they deliver their own radio chip some time in 2009, their reference design uses a Realtek transceiver chip. Both the Express Card and half-Mini Card reference designs are available for standard 3.1 GHz - 4.8 GHz operation but NEC can also provide support for products supporting the new 6 GHz high band. As far as I can tell, this is an industry first.
The reference designs also include drivers that have been extensively tested to render them as bomb-proof as possible with a wide variety of PC OSs. NEC says that they hope to eliminate the need for separate drivers in Windows-based applications if Microsoft ever includes Wireless USB in its Windows Drivers Suite but I’d caution that between Redmond’s glacial approach to embracing I/O technology that they did not invent and the fractious nature of the electronics industry’s politics, I would not expect this to happen any time soon.
It’s tough to say which of the two competing standards for Wireless USB will eventually dominate the market but, Intel’s decision to license its WACI host controller interface to NEC for their new products certainly adds to the momentum that the PCI/PCIe-oriented technology will enjoy. In the end, I think that the HWA standard, which is based on a USB 2.0 host connection, will find a smaller but viable market share because of the ubiquitous availability of USB connections as well as its lower implementation cost.
Samples of the uPD720171 are available now at $10.00 each. Demonstration boards are also available.
Product Brief
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